/*************************************************************************/ /* audio_effect_distortion.cpp */ /*************************************************************************/ /* This file is part of: */ /* GODOT ENGINE */ /* https://godotengine.org */ /*************************************************************************/ /* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */ /* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */ /* */ /* Permission is hereby granted, free of charge, to any person obtaining */ /* a copy of this software and associated documentation files (the */ /* "Software"), to deal in the Software without restriction, including */ /* without limitation the rights to use, copy, modify, merge, publish, */ /* distribute, sublicense, and/or sell copies of the Software, and to */ /* permit persons to whom the Software is furnished to do so, subject to */ /* the following conditions: */ /* */ /* The above copyright notice and this permission notice shall be */ /* included in all copies or substantial portions of the Software. */ /* */ /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */ /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */ /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/ /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */ /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */ /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */ /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /*************************************************************************/ #include "audio_effect_distortion.h" #include "core/math/math_funcs.h" #include "servers/audio_server.h" void AudioEffectDistortionInstance::process(const AudioFrame *p_src_frames, AudioFrame *p_dst_frames, int p_frame_count) { const float *src = (const float *)p_src_frames; float *dst = (float *)p_dst_frames; //float lpf_c=expf(-2.0*Math_PI*keep_hf_hz.get()/(mix_rate*(float)OVERSAMPLE)); float lpf_c = expf(-2.0 * Math_PI * base->keep_hf_hz / (AudioServer::get_singleton()->get_mix_rate())); float lpf_ic = 1.0 - lpf_c; float drive_f = base->drive; float pregain_f = Math::db2linear(base->pre_gain); float postgain_f = Math::db2linear(base->post_gain); float atan_mult = pow(10, drive_f * drive_f * 3.0) - 1.0 + 0.001; float atan_div = 1.0 / (atanf(atan_mult) * (1.0 + drive_f * 8)); float lofi_mult = powf(2.0, 2.0 + (1.0 - drive_f) * 14); //goes from 16 to 2 bits for (int i = 0; i < p_frame_count * 2; i++) { float out = undenormalise(src[i] * lpf_ic + lpf_c * h[i & 1]); h[i & 1] = out; float a = out; float ha = src[i] - out; //high freqs a *= pregain_f; switch (base->mode) { case AudioEffectDistortion::MODE_CLIP: { float a_sign = a < 0 ? -1.0f : 1.0f; a = powf(abs(a), 1.0001 - drive_f) * a_sign; if (a > 1.0) { a = 1.0; } else if (a < (-1.0)) { a = -1.0; } } break; case AudioEffectDistortion::MODE_ATAN: { a = atanf(a * atan_mult) * atan_div; } break; case AudioEffectDistortion::MODE_LOFI: { a = floorf(a * lofi_mult + 0.5) / lofi_mult; } break; case AudioEffectDistortion::MODE_OVERDRIVE: { const double x = a * 0.686306; const double z = 1 + exp(sqrt(fabs(x)) * -0.75); a = (expf(x) - expf(-x * z)) / (expf(x) + expf(-x)); } break; case AudioEffectDistortion::MODE_WAVESHAPE: { float x = a; float k = 2 * drive_f / (1.00001 - drive_f); a = (1.0 + k) * x / (1.0 + k * fabsf(x)); } break; } dst[i] = a * postgain_f + ha; } } Ref<AudioEffectInstance> AudioEffectDistortion::instance() { Ref<AudioEffectDistortionInstance> ins; ins.instance(); ins->base = Ref<AudioEffectDistortion>(this); ins->h[0] = 0; ins->h[1] = 0; return ins; } void AudioEffectDistortion::set_mode(Mode p_mode) { mode = p_mode; } AudioEffectDistortion::Mode AudioEffectDistortion::get_mode() const { return mode; } void AudioEffectDistortion::set_pre_gain(float p_pre_gain) { pre_gain = p_pre_gain; } float AudioEffectDistortion::get_pre_gain() const { return pre_gain; } void AudioEffectDistortion::set_keep_hf_hz(float p_keep_hf_hz) { keep_hf_hz = p_keep_hf_hz; } float AudioEffectDistortion::get_keep_hf_hz() const { return keep_hf_hz; } void AudioEffectDistortion::set_drive(float p_drive) { drive = p_drive; } float AudioEffectDistortion::get_drive() const { return drive; } void AudioEffectDistortion::set_post_gain(float p_post_gain) { post_gain = p_post_gain; } float AudioEffectDistortion::get_post_gain() const { return post_gain; } void AudioEffectDistortion::_bind_methods() { ClassDB::bind_method(D_METHOD("set_mode", "mode"), &AudioEffectDistortion::set_mode); ClassDB::bind_method(D_METHOD("get_mode"), &AudioEffectDistortion::get_mode); ClassDB::bind_method(D_METHOD("set_pre_gain", "pre_gain"), &AudioEffectDistortion::set_pre_gain); ClassDB::bind_method(D_METHOD("get_pre_gain"), &AudioEffectDistortion::get_pre_gain); ClassDB::bind_method(D_METHOD("set_keep_hf_hz", "keep_hf_hz"), &AudioEffectDistortion::set_keep_hf_hz); ClassDB::bind_method(D_METHOD("get_keep_hf_hz"), &AudioEffectDistortion::get_keep_hf_hz); ClassDB::bind_method(D_METHOD("set_drive", "drive"), &AudioEffectDistortion::set_drive); ClassDB::bind_method(D_METHOD("get_drive"), &AudioEffectDistortion::get_drive); ClassDB::bind_method(D_METHOD("set_post_gain", "post_gain"), &AudioEffectDistortion::set_post_gain); ClassDB::bind_method(D_METHOD("get_post_gain"), &AudioEffectDistortion::get_post_gain); ADD_PROPERTY(PropertyInfo(Variant::INT, "mode", PROPERTY_HINT_ENUM, "Clip,ATan,LoFi,Overdrive,WaveShape"), "set_mode", "get_mode"); ADD_PROPERTY(PropertyInfo(Variant::REAL, "pre_gain", PROPERTY_HINT_RANGE, "-60,60,0.01"), "set_pre_gain", "get_pre_gain"); ADD_PROPERTY(PropertyInfo(Variant::REAL, "keep_hf_hz", PROPERTY_HINT_RANGE, "1,20500,1"), "set_keep_hf_hz", "get_keep_hf_hz"); ADD_PROPERTY(PropertyInfo(Variant::REAL, "drive", PROPERTY_HINT_RANGE, "0,1,0.01"), "set_drive", "get_drive"); ADD_PROPERTY(PropertyInfo(Variant::REAL, "post_gain", PROPERTY_HINT_RANGE, "-80,24,0.01"), "set_post_gain", "get_post_gain"); BIND_ENUM_CONSTANT(MODE_CLIP); BIND_ENUM_CONSTANT(MODE_ATAN); BIND_ENUM_CONSTANT(MODE_LOFI); BIND_ENUM_CONSTANT(MODE_OVERDRIVE); BIND_ENUM_CONSTANT(MODE_WAVESHAPE); } AudioEffectDistortion::AudioEffectDistortion() { mode = MODE_CLIP; pre_gain = 0; post_gain = 0; keep_hf_hz = 16000; drive = 0; }